The invention provides a method for preparing multi-element-
doped carbon materials by utilizing Chinese chives. The method comprises the following steps: adding Chinese chives together with
ammonia water and ultra-pure water to a
hydrothermal reaction kettle to be subjected to
hydrothermal reaction; after the
hydrothermal reaction is finished, performing natural cooling, and then pouring out the reaction liquid in the hydrothermal reaction kettle; and performing
centrifugation,
filtration and
freeze drying to obtain
nitrogen,
sulfur and
phosphorus co-
doped carbon quantum dots. The raw materials used in the method provided by the invention are cheap and easily available, and carbon
nanorod materials are also obtained while carbon
quantum dot materials are prepared, so that efficient utilization of common
biomass resources is realized. The preparation method provided by the invention has the advantages of low cost, greenness and
environmental protection, simple operation, low requirements for equipment, and convenience for large-scale preparation and industrial production; the obtained
carbon quantum dots have the advantages of good water
solubility, high purity, good dispersibility,
uniform size, high stability and high
heteroatom doping content, wherein the
nitrogen content is as high as 6.8%, the
sulfur content is as high as 5.2%, and the
phosphorus content is as high as 4.5%;and an obtained
macroporous carbon material has a
large pore structure dimensionally and mutually communicated.